Tetanus is usually caused by Clostridium tetani infection. Clostridium tetani is usually present in deeper wounds or contaminated wounds, for example, a rusty nail piercing the foot must be given a tetanus shot. Because the wound may be deeper and at the same time the rust may contaminate the wound, tetanus must be injected. For example, if there is a superficial scratch, because the wound is relatively shallow, it may not damage the dermis and is in an open state, so Clostridium tetani is not easily infected. For children, because the vast majority of children have received the tetanus vaccine, if parents confirm that their child has been vaccinated and has antibodies for ten years, unless the wound is particularly contaminated and requires another booster shot of tetanus vaccine, there is no need to go back for another vaccination for ten years.